In order to assist in keeping various types of commercial and industrial establishments clean and neat in appearance, and particularly in keeping the floor clean and polished, various functions are performed thereon. Floor maintenance jobs which are performed include scrubbing, spot-cleaning, stripping, spray buffing, polishing, shampooing, and, in some circumstances, even sanding. Various types of devices have been designed to accomplish these functions. The typical floor treating machine known in the art has a rotating pad including a treating surface which moves in a generally horizontal plane. In the majority of instances, these machines are electrically operated, having a motor to impart rotation to the treating pad and a power cable which can be plugged into a conventional electrical wall outlet to provide a source of power for the motor.
Depending upon the function and application to which the machine is to be put, it is desirable that the machine possess a feature whereby the speed at which the treating pad rotates can be varied. Low speed machines are desirable for scrubbing floors, applying wax finishes to floors, stripping wax build-up from floors, and sanding or polishing floors. High speed machines are desirable for effecting final polishing or burnishing floors. Floor surfaces can, thereby, be brought to a high luster to provide a desirable appearance and ease of maintenance.
In order to effect the lower speed functions, it is desirable that the treating pad be made to rotate at 150-225 rotations per minute, in order to effect higher speed functions, it is desirable that the treating pad be made to rotate at 900-1200 rotations per minute. In machines known in the art, speed ranges are typically changed by varying the speed of the motor. The means by which this is accomplished typically include electrical devices intergral with the circuitry of the motor. Frequently, a switching mechanism is used to effectuate the speed range change. The switching mechanism can be changed by a toggle or similar switch mounted proximate the handle of the machine.
Even when using such speed change means, however, the desirable ranges of approximately 200 rotations per minute and 1200 rotations per minute cannot be accomplished within the same machine. This is due, in a significant part, because of the limitations inherent in electrical motors. In floor treating machines wherein change of speed of rotation of the treating pad is effected by changing the speed of the motor, therefore, the speed range is typically limited to a low speed range (approximately 200 rotations per minute) and a medium speed range (varying between 300-500 rotations per minute).
Even if the desirable speed ranges were obtainable, machines wherein the speed of the motor is varied have other limitations. By varying the speed of the motor, the horsepower output varies commensurately. Consequently, although such a machine may operate at an optimum efficiency at one of its speeds, something less than maximum efficiency is achieved at its other speed.
It is to these limitations and problems in the prior art that the invention of the present application is directed. It provides apparatus wherein speed of the machine can be varied between a low speed range (approximately 200 rotations per minute) and a high speed range (approximately 1200 rotations per minute), and wherein the speed variation is accomplished by mechanical means without the power output of the machine fluctuating.